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reef

Winter Model Discussion - Cold Hunting 08/01/13 00z Onwards

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Always a problem if you look at a run such as the 18z, nothing but the same will quite hit the spot. I really dont see where the mild and wet comes from, from some guys , i see battleground over the uk smile.png

ensembles?....sure we would of snapped their hand off if it showed us this a few short days ago smile.png

MT8_Manchester_ens.png

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As a real novice here, I just don't understand how 6 hours can make all the difference. Last night most posters were bullish and this morning you'd think the whole think had be cancelled. Just doesn't make sense to the casual reader.

ask John Holmes about that !!

people compare run against each other like the 0z against the 12 z against 18 z

if you actually stick with one run a day and compare it to it former you can see if any trends are beginning to take shape , the 12z suite are probably the best as they same to have higher verifying stats

Ive been watching the 18z only cause its developed the pacific ridge and later on the GH block more in line with the anaomaly charts , over the last 2 days its been relative stable considering its still in the T192 zone

will it end up like that , who knows and the sad thing we probably have another 5-7 days of ups and down til the later part of the month comes into more reliable forecasting zone

enjoy

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The pattern is beginning to take shape. We are heading for an initial cold snap (at least) from Saturday. After that D7/8 the ens are no use because of the split on D5. Both ECM and GFS support this cold snap. The former is more E/S/SE centric for the real cold uppers. ECM then continues with the Atlantic push with its op. The GFS maintains a cool/cold pattern but has only minor support (at the moment) from its ensembles.

The GFS op is a mild option for the cold snap (along with the control). The majority of the members bring in deeper cold (850s) and probably a better wintry perspective: post-14819-0-39241800-1357631855_thumb.p

So still promising for cold from the end of the week. Once the extent of that is resolved we can be more confident of the ensembles further into FI.

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Good morning Ian, I hope Ian F does not mind me using his post from last night, but if you read this and also consider Matt Hugo's post this morning I think they provide a much more balanced veiw than reacting to one or two poor model runs which we have been constantly warned will be all over the place for some time.

#1381 fergieweather

Posted Today, 00:28

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Very latest UKMO guidance just issued goes for the cold/v cold story predominanting into next week with potential sequence of battleground set-ups of snow to rain and back again in W/SW ; heavy snow potentially in any region; perhaps with a temporary relaxation of pattern but return of cold thereafter (MOGREPS keeping a N'rly well into 10-15d trend period)

One hopes so, but the thing is this situ at the moment seems to be so dynamic.

My knowledge is limited compared to some on here but apparently any strat warming that's happened in last few days and forecast to happen over the coming weeks may NOT have an effect for a while yet anyway, so the 'experts' tell us.

BUT who's to say the UK doesn't stay on the 'wrong' side of the trough over next couple of weeks.

Maybe a couple of bites at the cherry, so to speak over the next 10 days?

Fascinating stuff at the mo, if one likes to watch continuous drama!

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I think there are two broad solutions on the table for next week and ecm is caught between them. I think the way it is resolving the two is wrong and hence its output in the mid range is suspect. Fwiw, i think option 1 is for the scandi ridge to be more persistant and for the energy from the nw to be sinking se across nw europe (sort of repeating pattern of this weekend but maybe further east at times). Option 2 is for the height rise into greenland becoming cut off and subsequent undercutting scenarios with energy approaching the sw uk.

As ever, we will see.

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As a real novice here, I just don't understand how 6 hours can make all the difference. Last night most posters were bullish and this morning you'd think the whole think had be cancelled. Just doesn't make sense to the casual reader.

Unfortunately it's because we are a billion miles away from being able to forecast the weather more than 2 to 3 days ahead. Just watch the models change daily, sometimes beyond compare to the previous days output to see that they just can't keep up with the ever changing Synoptics.

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Models keep changing!!

ECM great in the shorter term this morning

http://www.wetterzentrale.de/pics/Recm961.gif

GEM snowy as well

http://www.wetterzentrale.de/pics/Rgem1081.gif

GFS best in FI

http://www.wetterzentrale.de/pics/Rtavn3001.png

UKMO 144 highlights divergence with Atlantic pattern and continuation of cold

http://www.wetterzentrale.de/pics/Rukm1441.gif

ECM pushes the Atlantic over the top

http://www.wetterzentrale.de/pics/Recm1441.gif

GFS somewhere in-between

http://www.wetterzentrale.de/pics/Rtavn1441.png

Fascinating model watching, many options still available, little cross model agreement in what will happen next week.

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Good morning. Apologies for no report last night. I felt a little under the weather (forgive the pun). However, Here is the report on the 00zs from GFS, UKMO, GEM and ECM for today Tuesday January 8th 2012.

All models continue to show some rather colder air moving in after the recent mild weather. Some rain is to be expected today and again on Thursday and probably Saturday too as troughs move in from the West. In between drier spells with some sunshine is shown as ridges of High pressure crosses from the West in an airflow which gradually becomes chillier as time passes.

GFS then shows the weekend being unsettled and rather cold as Low pressure drifts East to the South with rain here with the chance of some sleet or wet snow on the hills for a time. It then clears away East to be followed by further Low pressure drifting SE over NE areas with further chilly weather with rain at times in a chilly NW wind. In FI today Low pressure slides SE from the Atlantic as pressure builds strongly to the North. Winds back towards the SE with the Low becoming dominant to the South and SW with spells of rain and strong East or NE winds turning any rain rapidly to snow with widespread disruption likely in the South and East should the FI charts verify right out to the extremities of FI.

The GFS Ensembles show a rather colder spell than what we have been accustomed of late. The Operational above was one of the colder options on offer with some rather milder options on offer too. Overall the most likely trend from this morning's output is for temperatures to be rather below normal with some snowfall possible, especially but not necessarily exclusively on the hills in the North.

The Jet Stream shows the current flow soon to ridge High to the North of the UK while a new Southern arm though weak takes the flow over France for a few days before in a week or so before the flow ridges strongly over the Atlantic and dives South over the UK in a week to 10 days time.

UKMO for midnight on Monday shows High pressure off SW Ireland with dry and rather cold and frosty conditions everywhere with some pleasant if cold sunny spells likely on the day that follows.

GEM shows the South still under influence of a Low pressure well to the South on Monday with a cold East wind but by then it is likely to be dry. Over the following days the weather stays mostly dry as a ridge collapses slowly SE over Britain with dry, bright days mixed with cold and frosty nights look likely.

ECM shows a cold ridge lying NE across the UK with cold and bright conditions with frosty nights looking likely before the trend to milder SW winds and some rain look likely late in its run with temperatures returning to normal.

In Summary this morning the models are staggering their way to something rather colder. The path to it though is slow and hesitant, mostly due to high heights down to the SW failing to link to High pressure at more Northern latitudes, while allowing Low pressure to sink SE over the UK or just to the East feeding none too warm but never very cold NW winds for many at times. The GFS operational just shows what could happen if the pattern backs West with a cold and snowy end to its run. With many twists and turns to be expected in the output over the coming days it's going to be a long and bumpy road still if it's widespread cold and snow that your looking for.

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No it was the ECM that first picked up the shortwave off Southern Greenland in late November. The GFS was first to show the Norwegian shortwave in December that scuppered the Easterly.

Just really disappointed for everybody, let's see what Ian F has to say and see if the METO change their outlooks later.

Why would the METO change their outlook based on one set of runs that doesn't show feet of snow outside everybody's front door??

Last night we were set for a real snowy blast, this morning you're disappointed for everybody. Come off it Ian, you know as well as anybody else how volatile the models are currently. Why is this scenario any more likely to verify than the 18z from last night??

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The 00z runs still trending cold from the weekend.

post-2026-0-96479200-1357632733_thumb.pnpost-2026-0-68191600-1357632747_thumb.pn

as ever some differences later on but we know this will happen.

GFS temps ens.

post-2026-0-11360400-1357632759_thumb.pn

who said the cold has been delayed? some bitter days and nights to come.

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Can I just say to all the doom mongerers, don't forget it was only yesterday when a Professional told us that the models are NOT yet handling the SSW, and that the charts are just showing a 'normal' winter pattern. Liam Dutton also said the same in his blog.

From this I deduce that once the SSW starts to show its hand in the models, then we will more likely see more consistency and more favourable charts.

The only question that remains for me is, *when* will the SSW starts showing its hand, or will it not at all?

The only model that factors in the goings on in the strat is the GloSea4, which we mere mortals do not see.

So for me I'll be sticking to the more balanced views and giving the 'glass half empty' outlook posts a wide berth.

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The Ecm 00z is looking mild at T+240 hours, compare that to the Gfs 00z in the same timeframe and we can see there is a widening gulf developing between the big two models, the ecm 00z does delay the return to average/milder relative to the 12z last night but the sw/ne jet tilt is still returning, the gfs shows a stunning FI from a cold perspectives, some really eye popping charts with lows undercutting the cold block and a snowfest freeze for the uk, the ecm in comparison is a return of the same old bland mild weather which has dominated the last 3 weeks.

post-4783-0-37491000-1357632988_thumb.pn

post-4783-0-70085700-1357633043_thumb.pn

post-4783-0-81323200-1357633072_thumb.pn

post-4783-0-48332300-1357633100_thumb.pn

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Good morning Ian, I hope Ian F does not mind me using his post from last night, but if you read this and also consider Matt Hugo's post this morning I think they provide a much more balanced veiw than reacting to one or two poor model runs which we have been constantly warned will be all over the place for some time.

#1381 fergieweather

Posted Today, 00:28

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Very latest UKMO guidance just issued goes for the cold/v cold story predominanting into next week with potential sequence of battleground set-ups of snow to rain and back again in W/SW ; heavy snow potentially in any region; perhaps with a temporary relaxation of pattern but return of cold thereafter (MOGREPS keeping a N'rly well into 10-15d trend period)

Thanks for the info Ian, I'm liking the bold bits, living in the Cotswolds that sounds great.

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ECM is probably on the money - has been thus far so my gut feeling is don't get too excited about cold prospect as next week will probably be a 2 dayer cold blip at best before the Atlantic charges back through. Hope I'm wrong, really do but hey the express has gone for the next ice age which usually = mild mush a certainty! Lets hope the strat warming is bashing the nuts out of the ECM algorithms and the colder outputs are on the money :). As always MORE RUNS NEEDED!

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I agree that the GFS does handle heights over Greenland much better than the ECM, but the NAO remains a concern for me Fred, we really need to see this treading towards negative. Hopefully with the effects of a SSW still to have an impact, this will soon follow.

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The gfs looks messy with short waves crossing us and the Atlantic pushing in at times but it is GREAT for snow potential. Fits in nicely with met office guidance from Ian (above) Would rather this than bitter cold and dry!

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ECM is probably on the money - has been thus far so my gut feeling is don't get too excited about cold prospect as next week will probably be a 2 dayer cold blip at best before the Atlantic charges back through. Hope I'm wrong, really do but hey the express has gone for the next ice age which usually = mild mush a certainty! Lets hope the strat warming is bashing the nuts out of the ECM algorithms and the colder outputs are on the money smile.png. As always MORE RUNS NEEDED!

Thanks for that. Will be interesting to see the METO do a MASSIVE 'U' turn on the previous update we have had......

Very latest UKMO guidance just issued goes for the cold/v cold story predominanting into next week with potential sequence of battleground set-ups of snow to rain and back again in W/SW ; heavy snow potentially in any region; perhaps with a temporary relaxation of pattern but return of cold thereafter (MOGREPS keeping a N'rly well into 10-15d trend period).

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I doubt it, they have also warned us about model chaos and flip flopping, that is what we are seeing.

Ian, if you read this, could you let us know what GloSea4 is indicating (I'm told it's the best at handling stratospheric related events)

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I agree that the GFS does handle heights over Greenland much better than the ECM, but the NAO remains a concern for me Fred, we really need to see this treading towards negative. Hopefully with the effects of a SSW still to have an impact, this will soon follow.

I refer you to Ian Fergie's post last night.....There really is no 'sudden collapse' or game over situation. BFTP

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Good morning Ian, I hope Ian F does not mind me using his post from last night, but if you read this and also consider Matt Hugo's post this morning I think they provide a much more balanced veiw than reacting to one or two poor model runs which we have been constantly warned will be all over the place for some time.

#1381 fergieweather

Posted Today, 00:28

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Very latest UKMO guidance just issued goes for the cold/v cold story predominanting into next week with potential sequence of battleground set-ups of snow to rain and back again in W/SW ; heavy snow potentially in any region; perhaps with a temporary relaxation of pattern but return of cold thereafter (MOGREPS keeping a N'rly well into 10-15d trend period)

An excellent post to keep in mind before reaching for the razors and prozac folks. Now, much more than usual, there is no point getting so emotional about the vagaries of each run. As for moaning that the we aren't getting any cold, having a look at the 2m temps for London shows well below average temperatures being likely for the entirety of the run with a number of positively Arctic ensemble members by London standards. This would likely mean a below average January CET if continued wouldn't it? Something people would have been desperate for a few years back. Lastly I hope I don't hear that idiotic term 'faux cold' being bandied about because if it is cold on the ground then it IS COLD, we don't live at the 850hpa level last time I checked.

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As a real novice here, I just don't understand how 6 hours can make all the difference. Last night most posters were bullish and this morning you'd think the whole think had be cancelled. Just doesn't make sense to the casual reader.

:) .....I think you'll find it's all about where you are in this small island of ours - this site is seriously bad for your sanity - leave now while you have a chance.

Ian

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Shaking my head in disbelief this morning at some of the posts especially those on the 1st page. If you take a look at all the output then it isn't disappointing if you're preference is cold, if anything the reverse is true.

Firstly the period between +72 & +120 needs to be resolved. Take a look at the upper temps on the ECM at +96 and then compare with the GFS.

gfs-1-96.png?0

ECM0-96.GIF?08-12

If you also compare with the UKMO you will see that there is a difference in what could happen this weekend as the SW tracks SE. Like I said last night potential for rain to turn to snow or even consist more of snow if the colder uppers arrive from the E prior to the arrival of the SW.

Take a look at the +120 ensemble means because a cold E,ly flow is being projected by both of them which could bring snow showers into E areas.

EDM1-120.GIF?08-12

gens-21-1-120.png?0

Beyond this is a nightmare to predict. Personally based on all the output I see two options and unfortunately the ECM can't make up its mind between the two and shows neither. We could see the GH scenario as suggested by the GFS or another option is we retain E,lys. This mornings GEM is a good example of what I think may happen and that is a continuation of E,lys via HP to our E followed by a shift W of HP into Iceland/Greenland.

So in summary an excellent morning for coldies and the potential for the E,ly between +96 to +168 to upgrade remains an option and so does snowfall this weekend.

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Really do think there's too much negativity on here again this morning, obviously a concern that ECM has again produced on Op run which prevents rising heights over Greenland but would appear to an outlier again.

The Op starts to go against the mean around t144, notice the differential in pressure over Iceland.

http://www.wetterzentrale.de/pics/Recm1441.gif

http://www.wetterzentrale.de/pics/Reem1441.gif

By t168, even more of a difference.

http://www.wetterzentrale.de/pics/Recm1681.gif

http://www.wetterzentrale.de/pics/Reem1681.gif

No doubt plenty of drama still to come!

Regards,

Tom

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One has to remember that the SSW is akin to shuffling a deck of cards. Previously, at the end of last month, we could predict every card that was turned over and there were no aces in the pack. With the SSW that pack has been mixed up dramatically with the aces returned - and a few extras added on top. Now, we know the aces are in there (Greenland/Scandi blocking) and constantly expect it to be the next card, but in reality we just don't know whether the UK will turn one over - or will we be stuck with the rest of the pack?

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Just a quick one...

EC Det and Control both mild outliers with a greater portion of the EC ENS members keeping colder air (near -5C 850mb temps) over the UK for longer into next week.

However, there are a growing number of EC ENS members which support the broader EC pattern to have low pressure dominant over Greenland or to the NW of the UK rather than higher pressure and this, as a result, means that more of an Atlantic flow arrives anyway, it's just delayed. The longer term (288hr) and beyond is still a right'ol mess from anything from a serious NE'ly outbreak to mild SW'lies, so none the wiser long term.

It's finely balance right now and something will soon 'tip' either towards the EC solution, or the EC will come on board with the GFS for example and support more blocking to the NW, but for now, that is looking less likely.

Matt.

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